Question

A garden hose can fill a hot tub in 360 ​minutes, whereas the drain on a hot tub can empty it in 600 minutes. If the drain is accidentally left​ open, how long will it take to fill the​ tub?

Answer 1

900 minutes

Explanation:

1/360 of tub is filled every minute

1/600 of it is drained every minute

1/360-1/600=1/900 is filled every minute then

it takes 900 minutes.